A large group of children, on whom I have already collected language and other developmental data at 10, 13, 20, 24, 28, and 36 months of age, will be sampled again at 4,5,6, & 7 years of age. Questionnaires focused specifically on diagnosis reports, will be used to identify children with Specific Language Impairment (SLI). A group of children who have participated in laboratory studies will be given standardized tests of intelligence, phonology, vocabulary, and grammar so that their language status can be documented by behavioral measures. They will also receive experimental measures of discourse, grammar, word retrieval, and phonemic memory that will allow me to characterize the children to determine if (and what kind of) deficits remain. The establishment of this large, well defined cohort provides an unprecedented opportunity to examine the natural history of early language delay, from 10 months of age to school age. Specific goals include 1) identification of predictors of SLI documented at 4 to 7 years of age using behavioral, parent report, and medical-family history data obtained between 10 and 36 months of age, 2) examination of stability of language delay identified at 16 and 28 months of age through 7 years of age, 3) description of the different trajectories of development taken for vocabulary, grammar, and phonology by language delayed and typically developing children identified at 16 and 28 months of age through 7 years of age, and 4) examining specific language knowledge and processing skills known to be particular problems for children with SLI in children who had early language delay when they are 4 to 7 years old.